From: Arnd Bergmann <arnd@xxxxxxxx>
Using a kernel pointer in place of a dma_addr_t token can
lead to undefined behavior if that makes it into cache
management functions. The compiler caught one such attempt
in a cast:
drivers/net/wireless/ath/ath10k/mac.c: In function 'ath10k_add_interface':
drivers/net/wireless/ath/ath10k/mac.c:5586:47: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
5586 | arvif->beacon_paddr = (dma_addr_t)arvif->beacon_buf;
| ^
Looking through how this gets used down the way, I'm fairly
sure that beacon_paddr is never accessed again for ATH10K_DEV_TYPE_HL
devices, and if it was accessed, that would be a bug.
Change the assignment to use a known-invalid address token
instead, which avoids the warning and makes it easier to catch
bugs if it does end up getting used.
Fixes: e263bdab9c0e ("ath10k: high latency fixes for beacon buffer")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/wireless/ath/ath10k/mac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 7ca68c81d9b6..c0e78eaa65f8 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5583,7 +5583,7 @@ static int ath10k_add_interface(struct ieee80211_hw *hw,
if (ar->bus_param.dev_type == ATH10K_DEV_TYPE_HL) {
arvif->beacon_buf = kmalloc(IEEE80211_MAX_FRAME_LEN,
GFP_KERNEL);
- arvif->beacon_paddr = (dma_addr_t)arvif->beacon_buf;
+ arvif->beacon_paddr = DMA_MAPPING_ERROR;
} else {
arvif->beacon_buf =
dma_alloc_coherent(ar->dev,
--
2.29.2
